vxlan: allow choosing destination port per vxlan

Allow configuring the default destination port on a per-device basis.
Adds new netlink paramater IFLA_VXLAN_PORT to allow setting destination
port when creating new vxlan.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 5346131..b05823c 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -305,11 +305,12 @@
 	IFLA_VXLAN_LEARNING,
 	IFLA_VXLAN_AGEING,
 	IFLA_VXLAN_LIMIT,
-	IFLA_VXLAN_PORT_RANGE,
+	IFLA_VXLAN_PORT_RANGE,	/* source port */
 	IFLA_VXLAN_PROXY,
 	IFLA_VXLAN_RSC,
 	IFLA_VXLAN_L2MISS,
 	IFLA_VXLAN_L3MISS,
+	IFLA_VXLAN_PORT,	/* destination port */
 	__IFLA_VXLAN_MAX
 };
 #define IFLA_VXLAN_MAX	(__IFLA_VXLAN_MAX - 1)